1. Field of the Invention
The present invention relates to a liquid crystal display panel having an ion trap structure and a liquid crystal display including the same. More particularly, the present invention relates to a liquid crystal display panel having an ion trap structure to reduce an ion impurity concentration of liquid crystal so that the image quality of a liquid crystal display panel may be improved, and a liquid crystal display including the same.
2. Discussion of the Background
A residual image in a liquid crystal display results from various complex factors. It is known that ion impurities in liquid crystal play an important role in the occurrence of a residual image. The concentration of ion impurities in liquid crystal may increase due to problems occurring during the production of liquid crystal display panels, or due to continuous dissolution of ion impurities from various materials that constitute liquid crystal display panels, for example, color filter photoresists, silicon nitride layers, overcoat films, alignment films, and sealants. Ion impurities act as a leakage current while moving in a predetermined direction due to an electric field applied to the liquid crystal, which reduces the voltage holding ratio (VHR) of a liquid crystal capacitor. In addition, since ion impurities having positive and negative electric charges move in directions opposite each other due to an external electric field, an electric double layer may be formed, and subsequently, the voltage applied to the liquid crystal may change, resulting in the occurrence of residual images.
Although the voltage holding ratio may be improved by trapping ion impurities on a surface of a substrate, the occurrence of residual images due to the change in liquid crystal voltage may still occur.